It is always desired to increase the light emission from light packages. Certain types of light packages are designed with an encapsulating material surrounding the light source and the ultimate light emitting surface. For example, in light emitting diode (LED) packages an LED chip is positioned within a cavity formed by the light package housing. Encapsulating material surrounding the LED chip acts as interface between the LED chip and the outside world.
In such a structure, the light from the light source, such as from the LED chip, must pass through the encapsulating material before it emerges into the outside world through, for example, the top (or outer) surface of the encapsulating material.
In the past, one method of achieving increased light output from LED packages was to place photonic crystals around the LED chip to enhance the light emitting into the encapsulating material. This method has proven effective but still light is lost as it passes through and emerges from the encapsulating material.